The treatment of German physicists under the Nazi regime had far-reaching consequences both for the outcome of the Second World War and for the course of science for decades thereafter. Although this fact has been known from a few famous episodes, it has not been dealt with thoroughly by scholars because it involves two very different disciplines. Political historians have cautiously left it to historians of science, who in turn have shied away from it out of ignorance of the political intricacies. Alan D. Beyerchen here examines this history in detail, basing his research on archival materials in Germany and the United States and on tape-recorded interviews with leading physicists. At least twenty-five percent of Germany's academic physicists who were working in 1933 lost their positions during the Nazi period. The victims -- Jews and other ";politically unreliable"; persons -- included some of Germany's finest scientists. Those who remained faced opposition not only from Nazi officials but also from certain members of their own community, notably the Nobel laureates Philipp Lenard and Johannes Stark. Beyerchen describes the mechanisms of prejudice, the reaction to the dismissals, and the impact of the ";Aryan physics"; movement which ultimately failed.